Circuit breaker testing accessories

Contents Cables 3 DCM DualGround 8 Software 9 Application kits 9 Static and dynamic resistance measurement 11 Transducers 12 Linear 12 Rotary 13 Transducer accessories 13 Transducer mounting kits 14 Universal kits 14 Circuit breaker specific kits 15 Ready-to-use kits Rotary 16 Transducer mounting accessories 17 Other 19 Connecting and mounting guidance 23 SDRM Hook-up examples and cable designations 23 DualGround - safe testing 24 Transducer mounting examples 25 First trip measurement 26 Art No. ZI-AB03E Doc. AB0081GE V07a 2018 The word Megger is a registered trademark 2016-2018, Megger Sweden AB. All rights reserved

Cables Analogue Input XLR / Banana Cable Analogue XLR / open ends XLR female / 4 mm safety plugs, 1 m (3.3 ft). For customized analog transducer connection X X X X GA-00040 Extension cable Analogue Input XLR female / open ends, 1 m (3.3 ft) X X X X GA-00041 Transducer cable, XLR / IP / TS For analog input, XLR3 female / XLR3 male Analog cable /TM, 7.5 m (24.6 ft) X X X X GA-00042 Transducer cable, XLR / TLH / LWH NOVOTECHNIC IP / TS, 1 m (3.3 ft) X X X X GA-00044 Transducer cable XLR / LWG NOVOTECHNIC TLH / LWH, 0.5 m (1.6 ft) X X X X GA-00049 NOVOTECHNIC LWG / M12, 0.5 m (1.6 ft) X X X X GA-00050 AB0081GE ZI-AB03E 3

Cable Current clamp Cable, extension Timing MAIN For current clamp, BNC / XLR3, 0.3 m (1 ft) X X X X GA-00140 Extension cable for time measurement of main contacts, XLR5 female / XLR5 male 10 m (32.8 ft) X GA-00150 Cable, Timing 5 m (16.4 ft) X GA-00155 Cable, Timing AUX Timing 5 m (16.4 ft) XLR5 / 4 mm banana incl. clamps X GA-00160 Cable, Voltage sense AUX1&2, timing 2 m (6.5 ft) XLR5 / 4 mm banana excl. clamps X GA-00170 Cable set, Timing TM1800 AUX AUX MAIN AUX SDRM Voltage sense cable incl. clamps, 2 m (6.5 ft) X GA-00175 The cable sets consist of 8 cables with clamps and 4 mm stackable safety plugs. For timing of CB contacts. 5 m (16.4 ft) X X X GA-00231 10 m (32.8 ft) X X X GA-00241 15 m (49.2 ft) X X X GA-00251 20 m (65.6 ft) X X X GA-00261 25 m (82 ft) X X X GA-00271 40 m (131 ft) X X X GA-00281 4 ZI-AB03E AB0081GE

SCA600/Coax. Cable Extension cable Analogue input X X X GA-00750 Cable reel XLR female/xlr male 1 m (3.3 ft) X X X X GA-00760 20 m (65.5 ft), 4 mm stackable safety plugs Black X X X X GA-00840 Red X X X X GA-00842 Yellow X X X X GA-00844 Green X X X X GA-00845 Cable Timing MAIN Blue X X X X GA-00846 Extension cable Timing MAIN Timing M/R XLR3 male / banana, 5 m (16.4 ft), Length of the split portion (retractable sock), 2.4 m (8 ft) to 3.8 m (12 ft) X X GA-00850 Adapter for Doble digital transducer For Timing M/R modules, XLR3 male / XLR3 female, 10 m (32.8 ft) X X GA-00851 Adapter for Siemens digital transducer For Doble transd. X X GA-00867 For Siemens digital transducer X X GA-00868 AB0081GE ZI-AB03E 5

Adapter for Vanguard digital transducer Cable Timing AUX For Vanguard transd. X X GA-00869 Digital transducercable 4 Adapter for terminal block 4 Cable lug adapter 1 Cable, 5 m, (16.4 ft) X X GA-00870 Digital transducer extension cable For customized digital transducer connection RS422, SUB-D15 / open ends, 10 m (33 ft) X X GA-00885 Cable Digital TP1 and Rotary EIL RS422, SUB-D15 / SUB-D15, 10 m (33 ft) X X GA-00888 NOVOTECH Digital TP1 and Rotary Baumer EIL transducer cable, D-SUB 15 / M12 20 m (66 ft) X X GA-00887 Adapter for Elcon digital transducer Baumer digital cable 10 m (33 ft) X X GA-00889 For using Leine & Linde 530 digital transducer, 10 m (33 ft) X X GA-00890 For using Baumer BDH16.05A3600-LO-B, digital transducer, 10 m (33 ft) X X GA-00895 Heidenhein digital cable Digital transducer cable, Heidenhein, 10 m (33 ft) X X GA-00900 6 ZI-AB03E AB0081GE

Ethernet cable, network /1800 DCM extension cable Cable for connection to network/lan, RJ45 X X GA-00970 1 DCM extension cable, DIN 6, 10 m (33 ft) Old type X X GA-00998 Open analog cable GA-00999 1 DCM extension cable, DIN 7, 10 m (33 ft) Actual type. See /1800 DCM Extension cable on page 8 X X GA-00999 Extension cable Analogue Input For customized analog transducer connection,1 m (3.3 ft) X X X X GA-01000 Cable kit Control HV Timing cable kit For analog input, XLR3 female / XLR3 male Analog cable /TM, 10 m (33 ft) X X X X GA-01005 Control kit for three phases 5 Test clip 5 Adapter for terminal block 5 Cable lug adapter 5 5 m (16 ft) 2 0.25 m (10 ) 2 Jumper 1 Plastic box X X GA-90002 x 5 For Timing M/R modules, XLR3 male / XLR3 female 5 Cable,10 m (32.8 ft) GA-00851 X X GA-90005 AB0081GE ZI-AB03E 7

Connection kit for Control cables DCM DualGround DCM 5 Test clip 5 Adapter for terminal block 5 Cable lug adapter 1 Plastic box X X X X GA-90010 DCM DualGround Timing 3- channels 1 DCM Upgrade cable kit CG-19180 X BL-59190 /1800 DCM Upgrade cable kit /1800 DCM Extension cable kit 6-channels 2 DCM Upgrade cable kit CG-19180 X BL-59192 Cables for 3 channels addition DualGround upgrade from 3 to 6 channels Length of the 1-cable portion, 10 m (33 ft) Length of the 2-cable portion, 1.5 m (5 ft) 3 DCM cable units 6 Clamps KD-03040 X X CG-19180 DCM - TM1800 DCM Span extension cable DualGround cable, DIN 7, extension for 3 channels 10 m (33 ft) 3 x GA-00999 X X CG-19181 Module for TM1800 DCM Module 3 DCM cables, 12 m (39 ft) DCM to Timing M/R cable GA-12900 6 Clamps KD-03040 Accessory bag GD-31040 X CG-19190 DCM Module 6 DCM cables, 12 m (39 ft) DCM to Timing M/R cable GA-12900 12 Clamps KD-03040 Accessory bag GD-31040 X CG-19192 DCM Cable link Cable to extend the span in the /1800 DCM BNC / BNC, 2 m (6.6 ft) X X GA-00720 DCM to Timing M/R X GA-12900 8 ZI-AB03E AB0081GE

Software CABA Win Application kits First trip kit For /1800, incl. Ethernet cross-over cable X X CG-8000X For, incl. fiberoptics and USB interface X BL-8203X For, incl. USB cable X BL-8206X Upgrade to R04D X X X X CG-8010X Upgrade from R04 and lower to R06, including Test Plan Editor (TPE) X X X X CG-8040X For single operating mechanism, 1 + 3 clamps X X BL-90700 Synchro Switch Relay kit For three operating mechanisms, 3 + 3 clamps X X BL-90710 Synchronized Switching Relay test kit incl. accessories, software and cables (delivered in transport case) SSR kit for TM 1700/1800 X X CG-91200 VDS Adapter SSR for (incl. VD401) X BL-91200 Accessory for on-line timing of MV breakers. Enables on-line timing on circuit breakers installed in enclosed medium voltage substations. Adapted to connect directly to the capacitive VDS (Voltage Detection System) interface according to the IEC 61243-5 and VDE 0682 T415 standards. X X X XB-39260 AB0081GE ZI-AB03E 9

Transducer calibration kit Vibration kit Plate XB-39022 not included X X X X XB-39095 Vibration channel The Vibration kit extends TM1800 / / and CABA Win with the equipment and software required for recording and analyzing vibration signals at a circuit breaker. The kit includes the signal conditioning unit SCA606, the software CABA Win Vibration and one vibration channel. The vibration solution can be extended up to 6 channels. X X X BL-13090 Additional vibration channel to be used together with the Vibration kit. Each Vibration channel includes accelerometer, accelerometer adapter, cables to SCA606 and cables to TM1800 / / *. X X X XB-32010 10 ZI-AB03E AB0081GE

Static and dynamic resistance measurement SDRM201 SDRM202 SDRM202 Cable GB-03431 Included acessories: SDRM Cable GB-03431 SDRM multi cable extension, 10 m (33 ft) GA-12812 Voltage sense GA-00175 Voltage sense extension cable GA-00150 Current cable (red) GA-12820 Current cable (black) GA-12830 Clamps (2 pcs) KD-03040 Ground cable, 2.5 mm 2, 10 m (33 ft) GA-00208 Charger HC-04210 Accessory bag GD-31040 Case GD-00222 X CG-90250 Included accessories SDRM Cable for /1800 GB-03412 SDRM multi cable extension, 10 m (33 ft) GA-12812 Current cable, red, 2pcs, 3 m (9.8 ft) GA-12820 Current cable, black 2 pcs, 0.5 m (1.6 ft) GA-12830 Ground cable, 2.5 mm 2 10 m (33 ft) GA-00208 Charger HC-04210 Accessory bag GD-31040 Case GD-00222 X X CG-90200 Pack of 3 units (CG-90200) for circuit breaker with 2 Breaks/Phase X X CG-90230 SDRM Cable for GB-03421 SDRM multi cable extension, 10 m (33 ft) GA-12812 Current cable, red, 2 pcs, 3 m (9.8 ft) GA-12820 Current cable, black 2 pcs, 0.5 m (1.6 ft) GA-12830 Ground cable, 2.5 mm 2 10 m (33 ft) GA-00208 Charger HC-04210 Cable XLR/Banana 2 pcs. GA-00040 Accessory bag GD-31040 Case GD-00222 X CG-90210 SDRM Cable for GB-03431 SDRM multi cable extension, 10 m (33 ft) GA-12812 Voltage sense cable, 2 m (6.5 ft) GA-00175 Voltage sense extension cable, GA-00150 10 m (33 ft) Current cable, red, 2pcs, 3 m (9.8 ft) GA-12820 Current cable, black 2 pcs, 0.5 m (1.6 ft) GA-12830 Clamps (2 pcs) KD-03040 Ground cable, 2.5 mm 2 10 m (33 ft) GA-00208 Charger HC-04210 Accessory bag GD-31040 Case GD-00222 X CG-90220 SDRM Cable for /1800 Accessory bag GD-31040 X X CG-90205 SDRM Cable for Accessory bag GD-31040 Cable XLR/Banana 2 pcs. GA-00040 X CG-90215 SDRM Cable (CG-90205) SDRM Cable for Voltage sense extension cable 10 m (33 ft) GA-00150 Accessory bag GD-31040 Voltage sense cable, 2 m (6.5 ft) GA-00175 Clamps 2 pcs) KD-03040 X CG-90225 AB0081GE ZI-AB03E 11

Extension cable, SDRM201/202 Current cables and clamps for SDRM202 Extension cable for CG-90200 and CG-90210 10 m (33 ft) X X X X GA-12812 Transducers Cable, red 2.5 m (8.2 ft) X X X X GA-12820 Cable, black, 0.5 m (1.6 ft) X X X X GA-12830 Linear Analog TLH-150 150 mm (5.9 ) travel 1) X X X X XB-30016 TLH-225 225 mm (8.8 ) travel 1) X X X X XB-30017 TLH-500 500 mm (19.7 ) travel 1) X X X X XB-30020 TLH-750 750 mm (29.5 ) travel 1) X X X X XB-30022 TLH-1000 1000 mm (39.4 ) travel 1) X X X X XB-30023 1) Including cable, 0.5 m (20 ) GA-00049 LWG 150 150 mm (5.9 ) travel 2) X X X X XB-30116 LWG 225 225 mm (8.8 ) travel 2) X X X X XB-30117 LWG 500 500 mm (19.7 ) travel 2) X X X X XB-30120 2) Including cable, 0.5 m (20 ) GA-00050 TS 150 150 mm (5.9 ) travel 3) X X X X XB-30030 TS 50 50 mm (1.9 ) travel 3) X X X X XB-30031 TS 25 25 mm (1 ) travel 3) X X X X XB-30033 3) Including cable, 1 m (39 ) GA-00044 Digital Linear transducer TP1 300 mm Linear transducer TP1 500 mm NOVOTECHNIC TP1 (Highspeed design for Megger) 300 mm (11.8 ) travel Cable 10 m (33 ft) X X XB-39140 Cable 20 m (66 ft) X X XB-39145 NOVOTECHNIC TP1 (Highspeed design for Megger) 500 mm (19.7 ) travel Cable 10 m (33 ft) X X XB-39150 Cable 20 m (66 ft) X X XB-39155 The above transducers are also available in other lengths, please contact Megger for more information. 12 ZI-AB03E AB0081GE

Touchless linear digital transducer (kit) Rotary Analog Transducer kit Digital Transducer kit Transducer accessories Slider Magnetic band, 2 m (6 ft), XB-39250 Touchless linear digital transducer, SIKO, XB-39237 Cable, 10 m (33 ft), GA-00889 Clamping base, XB-39014 Flexible arm, XB-39012 X X XB-39230 Novotechnic IP6501 Cable, 1 m (39 ), Flex coupling, 6 mm Hexagon wrench X X X X XB-31010 Baumer EIL580-SC10.5RH.03600.A Flex coupling, 10/6 mm Hexagon wrench With Cable, 10 m (33 ft) X X XB-39130 With Cable, 20 m (66 ft) X X XB-39135 Slider for linear transducer TP1 X X XB-39199 AB0081GE ZI-AB03E 13

Transducer mounting kits Universal kits TLH / LWG / TP1 kit Transducer kit 500/600 mm For use with linear transducers (TLH/LWH/TP1) X X X X XB-39065 Single phase, Analog, Linear, 500 mm (19.7 ) X X X X XB-40101 Single phase, Analog, Linear, 600 mm (23.6 ) X X X X XB-40102 Single phase, Digital, Linear, 500 mm (19.7 ) X X XB-40105 Transducer kit 300 mm Single phase, Digital, Linear, 600 mm (23.6 ) X X XB-40106 Single phase, Analog, Linear, 300 mm (11.8 ) X X X X XB-40103 Single Phase, Digital, Linear, 300 mm (11.8 ) X X XB-40107 Transducer kit w/o transducer Same as corresponding above but without transducers. Rotary transducer mounting kit 3 phase, Analog, Linear, 300 mm (11.8 ) X X X XB-40104 3 Phase, Digital, Linear, 300 mm (11.8 ) X X XB-40108 Single phase, Analog, Linear, 500-600 mm (19.7-23.6 ) X X X X XB-40110 Single phase, Analog, Linear, 300 mm (11.8 ) X X X X XB-40111 3 phase, Analog, Linear, 300 mm (11.8 ) X X X XB-40112 Single Phase, Digital, Linear, 500-600 mm (19.7-23.6 ) X X XB-40113 Single Phase, Digital, Linear, 300 mm (11.8 ) X X XB-40114 3 Phase, Digital, Linear, 300 mm (11.8 ) X X XB-40115 For transducers XB-31010 and XB-39130 Clamping base XB-39014 Flexible arm XB-39021 Holder for angular transducer XB-39022 Plastic transport case XB-39023 Adapter M6/6 2 Nuts M6 XB-39025 Adapter M8/6 2 Nuts M8 XB-39026 Adapter M10/6 2 Nuts M10 XB-39027 Adapter M12/6 2 Nuts M12 XB-39028 Holder for dig. rotary EIL and linear LWG, Ø 36 mm XB-39005 X X X X XB-51010 14 ZI-AB03E AB0081GE

Universal transducer mounting kit Universal adapter for rotary transducer For linear and rotary transducers Magnetic base XB-39013 Clamping base XB-39014 Flexible arm XB-39021 Holder for angular transducer XB-39022 Plastic transport case XB-39023 Adapter M6/6 2 Nuts M6 XB-39025 Adapter M8/6 2 Nuts M8 XB-39026 Adapter M10/6 2 Nuts M10 XB-39027 Adapter M12/6 2 Nuts M12 XB-39028 Universal support XB-39029 Holder for dig. rotary EIL and linear LWG, Ø 36 mm XB-39005 X X X X XB-51020 Circuit breaker specific kits HPL kit (ABB) Universal adapter to breaker and drive types HPL/BLG 3AP1FG X X X X XB-51060 BLG kit (ABB) For use on ABB HPL circuit breakers X X X X XB-39080 LTB kit (ABB) For use on ABB mechanisms BLG 352, 352C, 1002 and 1002A X XB-39085 LTB Kit (ABB) For use on ABB LTB circuit breakers with 3-column stand X X X X XB-39090 Mounting kit, XB-51010 Universal adapter for rotary transducer XB-51060 X X X X XB-61010 AB0081GE ZI-AB03E 15

HPL/BLG Kit (ABB) Mounting kit XB-51010 Universal adapter for rotary transducer XB-51060 X X X X XB-61020 AHMA Kit (ABB) 3-Phase Diagnostic Set for ABB drive mechanism type AHMA 4/8 3 Transducers 3 Adapter cable GA-00044 Mounting details Transport case X X X XB-61030 AHMA Kit (ABB) 1-Phase Diagnostic Set for ABB drive mechanism type AHMA 4/8 1 Transducers 1 Adapter cable GA-00044 Mounting details Transport case X X X XB-61050 HMB Kit (ABB) For drive mechanism type HMB 4/8 Three phase set complete in case 3 PES-HMB8 Transducers 3 Adapter cable GA-00044 1 Transport case 3 Calibration Certificates X X X XB-61040 HMB Kit (ABB) Ready-to-use kits Rotary Analog 1-phase kit For drive mechanism type HMB 4/8 One phase set complete in case 1 PES-HMB8 Transducers 1 Adapter cable GA-00044 1 Transport case 1 Calibration Certificates X X X XB-61060 Incl. transducer XB-31010, mounting kit XB-51010 X X X X XB-71010 3-phase kit Incl. 3 x 1-phase kits XB-71010 X X X XB-71013 Digital 16 ZI-AB03E AB0081GE

1-phase kit Transducer XB-39130 Mounting kit XB-51010 With Cable, 10 m (33 ft) X X XB-71020 3-phase kit Transducer mounting accessories With Cable, 20 m (66 ft) X X XB-71022 3 x 1-phase kits XB-71020 X X XB-71023 3 x 1-phase kits XB-71022 X X XB-71025 Holder for transducer Flexible arm Holder for dig. rotary Baumer EIL and linear LWG, Ø 36 mm X X XB-39005 Switch magnetic base M8 bolt threads at the ends of the arms X X X X XB-39012 Clamping base For easy attachment of transducer mounting arrangements. Equipped with threaded hole suited for a Flexible arm. X X X X XB-39013 Flexible arm Clamp suited for a Flexible arm Jaw opening max 40 mm X X X X XB-39014 Holder for transducer This one is stronger than XB-39012 M8 bolt threads at the ends of the arms X X X X XB-39021 Holder for analog rotary transducer and Baumer BDH digital rotary transducer, Ø 55 mm X X X X XB-39022 AB0081GE ZI-AB03E 17

Universal support Flex coupling Suited for the Flexible arms. Rod length is 250 mm Jaw opening max 40 mm XB-39029 Flex coupling For shaft diam. 6 mm (for Novotechnic IP6501) X X X X XB-39030 Thread adapter kit Magnetic adapter for motion transducer fitting. Distance screw For shaft diam. 10 / 6 mm (for Baumer BDH) X X XB-39032 Imperial / metrics adapter kit for TLH / TP1 1 nut metrics, M5 1 spacer nut, M5 / UNF 10-32 1 spacer nut, M5 / UNC 1/4-20 1 nut, UNF 10-32 1 nut, UNC 1/4-20 X X X X XB-39036 For attaching rotary transducers on shaft ends. Ideal at first trip test when other mechanical attachment methods are impracticable. Fits to a 6 mm flex coupling. Super strong neodymium magnet. Fits with both resistive and incremental rotary transducers XB-39037 Rod for digital transducer TP1 Metrics (M5) / metrics (M5) for TP1 X X XB-39160 Rod for NOVOTECHNIC TP1, 300 mm (11.8 ) X X X X XB-39193 18 ZI-AB03E AB0081GE

Other Dolphin clamps Black, with connection for 4 mm banana plug X X X X 40-083220 Timing clamp Red, with connection for 4 mm banana plug X X X X 40-08322 Cable organizer Timing clamp for bolt head X X X X 53-31800 Long term monitoring LTM1 LTM2 VD401 Hook-and-loop straps, 10 pcs. X X X X AA-00100 EPROM to be mounted in the Starts measurement when there is a change at any of the time-measuring inputs. X BL-80010 Functions in the same way as a standard, but returns automatically to the READY state after measurement. X BL-80011 USB to fiber adapte Voltage divider, ratio 400/1 (for and with analog channel) X X BL-90070 Current CABA Hardware USB to fiber adapter X BL-90165 AC/DC clamp/clip-on/current probe, Fluke 80i-110s Current sensor kit 1 channel (Fluke 80i-110s incl. cable GA-00140) X X X X BL-90600 Current sensor kit 3 channels 3 x (Fluke 80i-110s incl. cables GA-00140) X X X BL-90610 Temperature sensor With the temperature sensor the ambient temperature is automatically recorded with each measurement and stored together with the test result. The temperature becomes a parameter in CABA Win. Suitable cable is the Analog cable, 10 m GA-01005. Range: -20 C to +50 C (-4 F to +122 F) Resolution: 0.5 C (0.9 F) X CG-90070 Thermopaper, for Fujitsu 114 mm, 30 m X X GC-00030 Box/24 pcs X X GC-00032 AB0081GE ZI-AB03E 19

Thermopaper Soft case 114 mm, Ø 40 mm X GC-00040 Clamp Made from sturdy nylon fabric X X GD-00340 Clamps X X X X KD-03040 Multipurpose Timing clamp, black, 4 mm banana X X X X XB-39200 Ferrite kit Multipurpose Timing clamp, red, 4 mm banana X X X X XB-39202 Accessory for timing of GIS circuit breakers using TM1800 with DualGround C-shape ferrite 7 XB-40010 I-shape ferrite 4 XB-40020 Round ferrite 4 30-67090 Hook and loop fastener 4 09-10140 Transport case GD-00440 User s Manual ZP-CG04E X X XB-40090 For more information about optional accessories please contact Megger 20 ZI-AB03E AB0081GE

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Connecting and mounting guidance SDRM Hook-up examples and cable designations Timing cable is included with the TM1800 timing module. Transducer cable is selected together with the the type of transducer used. Timing cable is included with the. Transducer cable is selected together with the the type of transducer used. Timing cable is an optional accessory to. Transducer cable is selected together with the the type of transducer used. Transducer cable is selected together with the the type of transducer used. AB0081GE ZI-AB03E 23

DualGround - safe testing The best way to provide safety in circuit breaker testing is to keep both sides of the circuit breaker grounded throughout the test. This will also make the test faster and easier. Minimum time shall be spent in the substation and focus shall be on the test rather than the equipment. Site preparation (isolate work area, apply safety ground, issue permit to work) Hook up test equipment. Issue sanction for test Authorised person removes the ground Perform testing Authorised person applies ground Cancel sanction for test. Disconnect test equipment Site closing (cancel permit to work, disconnect ground) Conventional vs. DualGround Site preparation (isolate work area, apply safety ground, issue permit to work) Hook up test equipment. Issue sanction for test Risky step left out Safe testing with both sides grounded Risky step left out Cancel sanction for test. Disconnect test equipment Site closing (cancel permit to work, disconnect ground) 24 ZI-AB03E AB0081GE

Transducer mounting examples Analog transducer mounted on a distribution circuit breaker 1. Clamping base 2. Flexible arm 3. Holder angular transducer 4. Novotechnik IP6501 5. Flex coupling 6. Bolt adapter 2 6 5 1 3 4 Analog transducer mounted on a distribution circuit breaker 1. Magnetic base 4 3 2. Flexible arm 3. Holder angular transducer 4. Novotechnik IP6501 5. Flex coupling 6. Bolt adapter 2 5 6 1 AB0081GE ZI-AB03E 25

First trip measurement When a fault occurs on a transmission or distribution line, the mission for the circuit breaker is to open the circuit to isolate the fault from the power source. A quick interruption of the current will avoid or limit damage to expensive equipment caused by the high fault currents. Why capture first trip Testing circuit breakers can be done in many ways, but one of the most common is timing of the main contacts, which gives a direct indication of the trip time. A typical procedure for performing a timing test on a circuit breaker is: 1. Open the CB 2. Disconnect the CB by opening the disconnector switches 3. Ground the CB 4. Perform the timing test Will the timing tests show the true trip time? Well, not necessarily. Consider a circuit breaker that has been in service without operating for many months, even years, before it was taken out of service for testing. It might then be suffering from a lack of or dried grease and maybe corrosion in its bearings. These problems can, and most probably will, slow down the first operation. The problem with this procedure is that the CB has been operated at least once before the testing procedure begins. This operation might be all it takes to shake off any corrosion problems or sticky bearings and bring the breaker s trip time up to standard. So when the actual timing test is performed, no problem exists and the service engineer thinks the breaker is in good shape and no further service is needed. Some moths later the corrosion is back and when a fault occurs the CB does not trip fast enough, or maybe not at all. This is why it is important to capture the first operation to reveal any problems with the CB. Figure 1. Point for measuring coil current and control voltage. Figure 2. Points for measuring the line currents. Since the CB is in service, the conventional way with leads across the CB cannot be used. Instead, three current clamps are used on the secondary side of the current transformer for each phase. For ordering information, see First trip kit on page 9. Perform a first trip test A good and time effective way to check the condition of a circuit breaker is to document its behavior at the first open operation after it has been idle for long time. The measurement and connections to the CB are carried out while it is still in service. The only way to measure the currents in a safe way is to use current clamps. For the coil current, either one or three clamps are needed depending on the number of operating mechanisms. The clamps shall be of DC type in order to manage all types of coils. Connecting current clamps to the CT s secondary winding makes it possible to check the transition of the line currents to zero during the opening of the CB contacts as well as the synchronization of the opening times on the three phases. The equipment needed for a first trip measurement depends on the configuration of the circuit breaker. All the connections are made inside the control cabinet. 26 ZI-AB03E AB0081GE